[LINK] "Life on Mars? Non-Detection of Methane Suggests No Modern-Day Microbes"

Adam Mann's Wired article outlines the latest discoveries relevant to possible Martian life. If nothing else, this sets the bar for possibly life pretty low: any Martian life produces either produces little methane, is very sparse, or both. Thoughts?

NASA’s Curiosity rover has sniffed the Martian atmosphere for methane and, so far, turned up empty. The much-anticipated measurement strikes a blow to the hope that previous hints of methane could have been an indication of life on Mars.

Methane, made of one carbon and four hydrogen atoms, is one of the simplest organic compounds. On Earth, 90 to 95 percent of methane in the atmosphere comes from biological activity, mainly methanogenic bacteria and cow farts. Geological activity such as water-rock interactions could have also produced the methane, which would also have overturned astronomers’ view that Mars is geologically dead in the modern age. Curiosity’s latest measurements seem to refute both ideas.

“So far we have no definitive detection of methane,” said chemist Chris Webster, instrument lead on Curiosity’s Sample Analysis at Mars (SAM) laser spectrometer, during at NASA press conference today. SAM is like the rover’s “nose,” able to test the Martian atmosphere and determine what chemicals are present.

In 2009, Michael Mumma of NASA’s Goddard Space Flight Center in Greenbelt, Maryland used an Earth-based telescope and found hotspots of methane that appeared seasonally. Methane is quickly destroyed by ultraviolet radiation in the Martian atmosphere, usually after only a few hundred years, so the gas could not be left over from some era millions of years ago. The detection excited much of the scientific community because these hotspots could have been areas where underground Martian microbes were alive on modern-day Mars.

Later measurements by both Mumma and other scientists cast doubt on these methane detections, and one of Curiosity’s main tasks has been to provide evidence one way or another. The probe used its Tunable Laser Spectrometer (TLS) and found the atmosphere is mainly composed of carbon dioxide, with trace amounts of argon, nitrogen, and oxygen.

[LINK] "G-Class Outliers: Musings on Intelligent Life"

Centauri Dreams' Paul Gilster makes an interesting observation about potentially habitable worlds and their stars. Bright G-class stars like the sun are hospitable to life for shorter periods than the more commoner, dimmer, K-class stars. This has implications for life on these worlds, and the sort of life to be detected on these worlds.

Note the comparatively brief window for multicellular life in planets orbiting F-class stars when compared to a G-class star like our Sun, and note too that K-class stars (Alpha Centauri B is the nearest example) offer a much longer period of clement conditions for any planets in their habitable zone. The figure does not display M-class red dwarfs, but there the picture changes entirely because these stars can burn for trillions of years depending on their mass. If we do discover that life is possible on planets orbiting red dwarfs, then the time frame for intelligence to develop is proportionately extended.

With the universe now thought to be some 13.7 billion years old, is it possible that most intelligent species simply haven’t had time to appear on the scene? With up to 80 percent of the stars in our galaxy being red dwarfs, we may exist early in the overall picture of living intelligence, and most of it may evolve around stars far different than our own. Yesterday I talked about our gradual tightening of the number for eta-Earth (ηEarth), the percentage of Sun-like stars with planets like ours in their habitable zone. What we are still in the dark about is eta-Intelligence (ηIntelligence), the percentage of habitable zone planets with life that evolve intelligent species.

But back to F, G and K-class stars and what we do know. The O’Malley-James paper makes the significant point that G-class stars have a window for multicellular life that, based on the solitary example of our own planet, appears roughly the same length as the developmental period needed to produce it. And after the era of multicellular life, as the parent star swells toward red giant status, the era of microbial life returns for a still lengthy stretch, though shorter than the one that began it. Thus the reasonable statement “It is entirely possible that some future discoveries of habitable exoplanets will be planets that are nearing the end of their habitable lifetimes, i.e. with host stars nearing the end of their main sequence lifetimes.”

Without any knowledge of ηIntelligence, we can’t know what happens as the multicellular window begins to close. But if intelligence is not rare, then we can conceive of advanced civilizations taking the necessary steps to ensure their survival, either through migration to other star systems or massive engineering projects in space, perhaps remaining near the parent star. The kind of ‘interstellar archaeology’ championed by those who search for Dyson spheres and other massive constructs is an attempt to find projects like these, a form of SETI that is not reliant on the intent of a civilization to make contact and one that does not assume radio or optical beacons.

[LINK] "Obama wins the election! (on Twitter)"

Zero Geography's Mark Graham has an amusing but informative post mapping mentions of the presidential candidates on Twitter.

Can Twitter predict the outcome of the US election[?] If our results are anything to go by then Barack Obama will be reelected. The data presented below are the result of some research that Adham Tamer, Ning Wang, Scott Hale and I (Mark Graham) carried out in order to see how visible both major presidential candidates are on Twitter.

We collected about 30 million geocoded tweets between Oct 1 and Nov 1 and pulled out all references to Obama and Romney. [. . .]

We see that if the election were decided purely based on Twitter mentions, then Obama would be re-elected. In fact, the only states that Romney would win are Maine, Massachusetts, New Mexico, Oregon, Pennsylvania, Utah, and Vermont. Romney also wins in the District of Colombia (we unfortunately didn't collect data on Alaska or Hawaii).

However, this drubbing that Romney receives in the Twitter electoral college belies the close nature of the final popular (Twitter) vote. There are a total of 132,771 tweets mentioning Obama and 120,637 mentioning Romney, giving Obama only 52.4% of the total (and Romney 47.6%). A breakdown that is remarkably similar to current opinion polls.

[. . . ]

What do these data really tell us? I doubt that they will accurately predict that Obama will win in Texas or that Romney will win in Massachusetts. But they do certainly reveal that many internet users in California, Texas, and much of the country prefer talking about Obama than Romney. We would need to employ sentiment analysis or manually read a large number of the election-related tweets in order to figure out whether we are seeing messages of support or more critical posts.

As people mentioned on Facebook when I shared the link, the Twitter-using population isn't representative of the general American population. For starters, it's substantially younger.

[LINK] "Teratocracy Triumphant?"

I'm boosting the signal for Jamais Cascio's essay at Open the Future.

Two of the most important pieces I've produced here at Open the Future concern teratocracy -- a neologism meaning "rule of monsters." The first, Fear of Teratocracy, outlines the core concept: American democracy is shifting from debates over policy to debates over legitimacy. The second, Teratocracy Rises, offers a set of examples of how attacks on the legitimacy of one's opponents is becoming attacks on the concept of democracy itself.

As I noted in Fear of Teratocracy, democracy isn't just defined by how you win -- i.e., with a majority/plurality of the vote.

Democracy is defined by how you lose, not (just) how you win.

The real test of whether a society that uses a plebiscite to determine leadership is really a democracy is whether the losing party accepts the loss and the legitimacy of their opponent's victory. This is especially true for when the losing party previously held power. Do they give up power willingly, confident that they'll have a chance to regain power again in the next election? Or do they take up arms against the winners, refuse to relinquish power, and/or do everything they can to undermine the legitimacy of the opposition's rule?

I strongly encourage you to re-read the entire essay. Here's why it matters: I strongly suspect that, regardless of who wins the US presidential election today, the United States is likely to be entering a period of a crisis of legitimacy. If Romney wins, the claims of voter suppression and out-and-out shenanigans (this is a less ambiguous example) will potentially leave many Democrats incandescent with anger, even more so than after the 2000 Supreme Court selection of George W. Bush -- because now it will be a "we can't let them get away with this again" scenario. If Obama wins, the already widely-extant opposition to his legitimacy as President among Republicans could explode; expect to see Twitter storms about secession and armed revolution, as well as the very real possibility of violence.

Thoughts, concerns, fears?

[DM] "On the factor of changing demographics in the 2012 United States election"

I've a links-heavy post at Demography Matters tracing the weakness of the Republican Party in the current election to the perception among large, growing, and increasingly visible groups like the United States' Hispanics that the political party is hostile to them.

Thoughts?

Now, to wait and see.